# A startup says a Claude-based agent chose a gene therapy and injected it into an epileptic mouse’s brain

> Exin Therapeutics’ CEO says the agent picked the therapy and the target from 19 vectors. A human surgeon opened the skull, and no preprint has been published.

- Publisher: JARRUS (@jarrus.tech), thejarrus.com
- Story date: Oct. 28, 2026 (2026-10-28)
- Published: 2026-11-07
- Tags: Anthropic, Agents, Health
- URL: https://thejarrus.com/en/news/exin-mouse-gene-therapy/

On Oct. 28, Gabriel Ocana-Santero, co-founder and CEO of the San Francisco biotech startup Exin Therapeutics, wrote on X that an AI agent had carried out a brain injection in a mouse model of epilepsy. The only first-hand source is that seven-post thread; the company has published no preprint or technical report. According to the CEO, the agent was given a spreadsheet of 19 gene therapy vectors, a mouse model of epilepsy, a motorized surgery rig with cameras and one goal: reduce seizures. The agent chose the therapy and the brain region itself, derived the coordinates by averaging three papers, and injected 250 nanoliters over five minutes.

A human surgeon performed the craniotomy; by the CEO's account the agent is not permitted to do that for safety reasons. Every irreversible step required human approval, fixed limits such as a cap on injected volume were set, and a veterinarian held a physical stop button that cuts power to every motor. After a disconnect threw off the calibration, the agent saw that a 34-millimeter target had been computed on a 30-millimeter rig, refused to move and, after a second attempt, wrote that it would not try a third time. WIRED reports that the problem was fixed by having a separate agent, which was not told a live surgery was under way, change the code; a procedure that normally takes about 45 minutes ran a little over an hour.

By the CEO's account, Opus 5.5 refused the task as soon as it detected biological content. Opus 5 completed the dry run and stopped at the start of the live surgery, and Sonnet 5 ran that surgery from beginning to end. The OECD's AI incidents monitor logged the event as a hazard on Oct. 30; the classification text on that page is AI-generated and is not an official OECD view. The effect of the therapy on seizures is unknown, and the team is waiting for results. Anthropic did not respond to WIRED's request for comment.

https://x.com/OcanaSantero/status/2115442964574908902

## Sources

1. [Gabriel Ocana-Santero (X): The Exin Therapeutics CEO’s seven-post thread: 19 vectors, the coordinates, 250 nanoliters, camera observations, the safety measures and the agent’s refusal. 1,674,447 views. The only first-hand source., Oct. 28, 2026](https://x.com/OcanaSantero/status/2115442964574908902)
2. [WIRED: An AI Agent Injected Drugs Into a Live Mouse’s Brain, Oct. 31, 2026](https://www.wired.com/story/an-ai-agent-did-brain-surgery-on-live-mouse/)
3. [OECD.AI: AI Agent Performs Autonomous Brain Injection on Live Mouse, Oct. 30, 2026](https://oecd.ai/en/incidents/2026-10-30-1958)

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